Drafting instrument and attachment



Nov. 5, 1929. H. 1.. coRwlN DRAFTING INSTRUMENT AND ATTACHMENT Filed Feb. 26, 1927 INVENTOR.

/V0//yAee 60//1 ATTORNEYS Patented Nov.5,1929 1,734,613

UNITE STATE T5 once HARRY LEE ooEwIN, E LOS ANGELES, CALIEQ NTA DBAIETING INSTRUMENT AND ATTACHMENT Application filed February 26', 1927. Serial No. 171,180.

This invention relates to instruments of the Fig; is an enlarged vertical section type known as self-adjusting spring bow comthrough the lower portion of the template passes, commonly called pile-drivers, and member and the central member. A the principal object of the invention is to Fig. 6 is a View similar to a portion of Fig. provide an instrument of this type which may 4: showing another form of template member. be used for drawing or inscribing figures Fig. 7 is a side elevation, partly broken which are non-circular in shape, such as away, of a pen attachment which may be used hexagons or squares or any polygonal figures, interchangeably wit-h the pencil attachment or ellipses or the like. shown in the preceding figures.

It is an object of this invention not only to Fig. 8 is a partly sectional side elevation of provide a complete instrument for this purthe lower portion of a modified form of the pose, but also to provide an attachment which invention. may be applied to an ordinary pile driver Fig. 9 is a section on line 99 in Fig. 8. or spring bow compass so as to enable it to The instrument shown in Figs. 1 to, 5

15 be used for the purposes above mentioned. inclusive comprises a central rod 1 having a The drafting instrument which I have desharp point 2 at its lower end for piercing'a vised for this purpose comprises in general a sheet of drawing paper or the like so as to vertical central rod or member which is prefhold such central member in fixed position erably pointed at its lower end, a scribing and having a knurled handle or knob 3 at its 20 member rotatably mounted on said central upper end by means of which it maybe member and having scribing means at its manually held in position. lower end, a template member secured or The scribing member may comprise a adapted to be secured to said central member, spring arm 5 carrying suitable scribing means and means on said scribing member engaging such as a pencil attachment 6 at its lower 25 said template member so as to cause the scribend and mounted at its upper end upon suping means thereon to inscribe a figure of the porting block 7 which is secured upon a same shape as said template member upon tubular sleeve or bearing means 8. Said sleeve rotation of said scribing member. The tem- 8 surrounds the central member 1 so. as to plate member is preferably detachably rotate freely around 'said central member.

30 secured to the central member so as to permit The central rod 1, however, projects sometemplate members of different shapes to be what below the lower end of said sleeve,'and used for drawing correspondingly shaped the projecting portion ofsaid rod is tapered figures. as at 23. Limited relative vertical movement Other features and objects of the invention of the sleeve 8 with respect to central member 35 will be apparent from the following descrip- 1 is also provided for, such movement being tion thereof. limited by small projections 9 on the central The accompanying drawings illustrate member, which limit the upward movement embodiments of my invention andreferring of sleeve 8 by engaging the bottom of recess thereto, 10 within said sleeve and limit the downward 1 40 Fig. 1 is a side elevation of an ordinary movement thereof by engagement with a form of pile driver or self-adjusting spring bushing member 11 which maybe screwed bow compass, with certain additional parts into the upper end of the said recess. Said attached thereto so as to enable it to perform bushing member may be provided with a the operations above described. knurled head 25 by means of which thescrib- 45 Fig. 2 is an end elevation thereof taken ing member may be manually rotated. from the left in Fig. 1. A small block 13 is formed on or secured to Fig. 3 is an endelevation taken from the the lower end of spring arm 5, andthe pencil right in Fig. 1. attachment 6 may have a shank portion en- Fig. 4 is a horizontal section on line 4:"4: gaging in a recess 15 in block 13 and secured 50 in Fig. 1 I therein by means of screw 16 and nut 17.

The pencil attachment 6 is provided in the usual manner with a removable lead or pencil point 18. The instrument further comprises an adjusting screw 19 threaded in the block 13 and engaging or bearing against sleeve 8 at its inner end so that by screwing said adjusting screw in or out the distance between the scribing means and the central member may bevaried so as to permit different sized figures to be drawn. All of the parts above described are found in the ordinary tye of pile driver or self-adjusting spring bow compass.

According to my invention, the instrument is further provided with a template member 22, which is shaped eXteriorly to correspondto the figures to be drawn and which is adapted to grip the tapering portion 23 at the lower end of the central member 1 as indicated at 23, upon being forcibly pushed on to said member, and to extend upwardly around the lower portion of sleeve 8, fitting loosely around said sleeve so as to permit the sleeve to turn without turning the template member. If desired, the template member may be permanently secured to the central member, as by welding or otherwise, but in general I prefer to make the same detachable therefrom in order to permit the use of templates of different sizes or shapes with the same instrument. Suitable guide means are provided on the scribing member for engaging the surface of the template member. Such guide means are preferably adjustable so as to provide for varying the size of the figure to be drawn, and may advantageously comprise an adjusting screw 24 threaded in the upper portion of the scribing means 6 as shown. A knurled lock nut 25 is also preferably provided for holding the adjusting screw in the position to which it is set.

In the operation of the above described device for the purpose of drawing or inscribing hexagons, the adjusting screw 19 is adjusted so as to hold the scribing member at the desired distance from the central rod. Adjusting screw 24 is then adjusted so as to just touch or press very lightly against one of the flat surfaces of template member 22, as indicated in Fig. 1, and lock nut 25 is tightened so as to hold the adjusting screw in this position. If the central member 1 is held in fixed position by means of handle .3, and the scribing member is revolved by means of the knurled head 25, the inner end of screw 24 will. follow the shape of template member 22, and the scribing means such as pencil point 18 will inscribe upon the paper or other material. 26 a hexagon, as indicated at 27.

It will be evident that the instrument may also be used in the ordinary manner of a spring bow compass, for drawing circles, by simply screwing the adjusting screw 24; outwardly so that it does not engage the template member 22.

In Fig. 6 I have shown a square template member 22 which is adapted for the drawing or'inscribing of squares as indicated at 29.

A pen attachment 30 is indicated in Fig. 7, which is also provided with a shank portion 1 1- for mounting on block 18 and is provided with a threaded opening 31 for receiving the adjusting screw 24 or a similar adjusting screw. Such pen attachment may therefore be substituted for the pencil attachment shown in Fig. 1, and the term scribing means as used herein should therefore be understood to include either pen or pencil means or any other means for marking or inscribing the desiredfigure.

In Fig. 8 I have illustrated a modified form of the invention in which the tubular sleeve 8 extends only to a position somewhat below the adjusting screw 19, and in which the tem plate member 22 fits fairly snugly around the central rod 1 below the lower end of said sleeve. A set screw 33 may advantageously be provided for rigidly securing the template member 22 to the central member 1. In this form of the invention the adjusting screw 24 is shown as threaded in block 13 instead of inthe upper portion of the pencil or pen scribing attachment. One advantage of this modification is that the separate pen and pencil attachments do not need to be threaded and provided with separate adjusting screws.

I have also shown, as in Fig. 9, that the template member may be made elliptical in shape so as to provide for the drawing and inscribing of ellipses and it will be apparent that any suitable shape of template member may be employed in connection with either the form of the invention shown in Fig. 1 or that shown in Fig. 8.

I claim:

1. A drafting instrument comprising a cen-' tral member, a template member secure thereto, a scribing member, means secured to said scribing member and mounted for rotation about said central member, said scribing member having scribing means thereon and also having means tending to hold said scribmg means inwardly toward said central member, and an ad ustmg screw mounted on said scribing member for movement toward or away from said template member and having its inner end adapted to slidingly engage the outer face of said template member so as to limit inward movement of the scribing means.

spring bow compass having a central member and a sleeve rotatably mounted thereon, said central member projecting somewhat below the lower end of said sleeve, said attachment comprising a template member formed to fit a 120. 2. An attachment for a self-adjusting elongated central member, a sleeve rotatably mounted on said central member and extending throughout the major portion of the height thereof, a template member secured to the lower portion of said central member and extending upwardly around the lower portion of said sleeve and having its outer face formed as a template, a scribing member secured to said sleeve and having scribing means at its lower end, means tending to hold said scribing member inwardly toward template member, and a guide member mounted 011 said scribing member and extending inwardly therefrom to engage said outer surface of the template member.

4. A drafting instrument as set forth in claim 3, said guide member comprising a screw threaded in said scribing member for inward and outward adjustment thereof.

5. A drafting instrument comprising a central member, a template member secured thereto, a scribing member, bearing means secured to said scribing member and mounted for rotation on and about said central member, scribing means on said scribing member, means tending to hold said scribing means inwardly toward said central member, an adjusting screw mounted on said scribing member and adapted to engage said template member so as to limit inward movement of the scribing means, and another adj usting screw mounted on said scribing member and adapted to engage said bearing means, whereby said scribing member may be guided, upon rotation thereof, by engagement of one or the other of said adjusting screws with said template member or said said bearing means.

6. A drafting instrument comprising a vertical rod pointed at its lower end, a template member secured to said rod, a sleeve rotatably mounted on said rod, scribing means, means connecting said scribing means to said sleeve and tending to resiliently hold said scribing means inwardly toward said rod, and an adjusting screw threaded in said scribing means for movement toward or away from said template member and having its inner end adapted to slidingly engage the outer face of said template member so as to limit the inward movement of the scribing'means and cause said scribing means, upon rotation, to follow the shape of said template member.

7. A drafting instrument as set forth in claim 6, and comprising in addition another adjusting screw on the scribing means havingits inner end adapted to engage said sleeve to cause said scribing means, upon rotation, to follow a circular path.

In testimony whereof I have hereunto subscribed my name this 19th day of February,

HARRY LEE CORWIN. 

